1. Field of the Invention
This invention relates to bird proofing assemblies, and more particularly to a device for preventing birds from alighting on certain surfaces.
2. Description of the Prior Art
One knows that birds often try to alight on even the narrowest surfaces that they can find on outer structures of buildings: window sashes, sills, ledges, statues, wall ridge, roof gutter, portal, bridge, tower, mast, etc.
This alighting and resting is a nuisance in that the birds, through their droppings, dirty and damage not only the landing surface, but also all outer structures of the building that are underneath.
Due to aesthetic reasons, and also to avoid irreversible damaging of the structure material, one is often obliged to deal with frequent and expensive renovation work of the damaged parts of the building.
Besides, such a building is quite often located next to human activities. This is for example the case in cities, where such birds' droppings as well as birds' cries might commercially impact a whole area, whether it be a living area, a mall area or restaurants.
One of the most efficient ways of preventing this nuisance consists in covering surfaces on which birds alighting is not welcome, with a device comprising a bottom base support from which extend upwardly birds' dissuasive spike elements.
It can be demonstrated that such a device does not hurt the birds but only prevents alighting and resting.
Such a device is described in European patent application number 0 340 108, published on Nov. 2nd, 1989. The base support of the device, having a smooth surface on both its sides, has a thickness purposely reduced for both cost and aesthetic impact on covered structures reasons.
For these two same reasons, the spike elements diameter is reduced whilst the distance between two adjacent spike elements depends on the size of the birds at which the device is aimed.
To ensure fastening of the spike elements to the base support, canals of a diameter slightly larger than that of the spike elements are drilled through the base support, in which said spike elements are introduced and fastened with a usual type of glue. The base support is also attached to the surfaces to be covered through usual gluing.
Such a system however features three main drawbacks:
The quality of fastening of the spike elements to the base support degrades with time, under the combined action of weather (sun, frost), and the repeated attempts by the birds to upset this obstacle to their alighting. Little by little, the glue degrades and the spike elements are then one by one pulled off the base support, thereby rending very quickly the system completely inefficient.
Weather is also harmful to the material of which the base support is made: it usually becomes inaesthetically yellowish, and loses its elastic properties, so that if a lateral pressure is exercised on a spike element by a bird, the base support will break around the point where the spike element is fastened, also rending the system completely inefficient.
The glue usually used to attach the base to the surfaces to be covered is also sensitive to weather conditions. Moreover, being in contact with the building, it is susceptible of degrading such a building by chemical reaction. Finally, if the system is taken away, particles at the surface of the building might be pulled off at the same time the glue is.